JP5223630B2 - Electronic control unit - Google Patents

Description

  The present invention relates to an electronic control device, and more particularly, to an electronic control device including a timer circuit that is constantly supplied with power separately from a control unit that is supplied with power when a power switch is turned on.

  Conventionally, as an electronic control device provided with this type of timer circuit, for example, there is an on-vehicle electronic control device that controls an engine of a vehicle.

  In this type of in-vehicle electronic control device, generally, when a vehicle ignition switch (hereinafter referred to as IGSW) is turned on, power is supplied to a microcomputer as a control unit, and the microcomputer controls a control target. When the IGSW is turned off, the power supply to the microcomputer is stopped, and the elapsed time from that time is measured by a timer circuit (for example, see Patent Document 1).

  When the timer circuit detects that the elapsed time from turning off the IGSW has reached the set time set to itself, it outputs a start signal, and the microcomputer supplies power to the start signal. There is also an apparatus for executing a specific process to be performed while the IGSW is turned off. And as such a specific process, there exists a diagnostic process (evaporative gas leak check) of an evaporation purge system, for example (for example, refer patent document 2).

  Such a timer circuit is called a soak timer. Further, as a diagnostic process of the evaporation purge system, a system for recovering the evaporation gas (evaporative gas fuel generated in the fuel tank) from the engine fuel tank is closed by an actuator and pressurized or depressurized. The pressure fluctuation is detected by a sensor, and the airtightness (that is, the presence or absence of leakage) of the system is inspected. Such an evaporative purge system diagnostic process (hereinafter referred to as an evaporative diagnostic process) is easy to evaporate the fuel in the fuel tank after the engine has been operated for a long time with a high load, and an accurate diagnostic result is obtained. Therefore, when a certain time has elapsed after the IGSW is turned off, the microcomputer is activated and executed.

  By the way, if the timer circuit is not normal, the time measured by the timer circuit is not reliable. For this reason, the control unit performs an abnormality detection of the timer circuit and activates the measurement time by the timer circuit or the timer circuit itself on the condition that the timer circuit is confirmed to be normal. Need to do. For example, in an electronic control device that performs the above-described evaporation diagnosis process, the microcomputer as a control unit functions on the condition that the timer circuit is functioning on the condition that the timer circuit is normal. It is prevented that the diagnosis process is performed at an inappropriate timing (specifically, timing earlier than scheduled after the IGSW is turned off). This is to avoid obtaining an erroneous diagnosis result.

  As an abnormality detection method for the timer circuit, there is a method of reading the timer value of the timer circuit at a predetermined interval and detecting the abnormality based on the read timer value. Specifically, when the microcomputer reads the timer value of the timer circuit and then determines that the predetermined time T has elapsed based on the internal timer of the microcomputer, the timer value of the timer circuit is read and read twice. There is a method of determining that the difference between the two timer values (that is, the increment of the timer value at the predetermined time T) is not within a specified range, and determining that the difference is within the specified range, and determining that the difference is normal if the difference is within the specified range ( For example, see Patent Documents 1 and 3).

  The timer value of the timer circuit is a count value of the timer circuit, and more specifically, a count value of a counter provided for measuring time in the timer circuit.

On the other hand, for example, Patent Document 4 describes the RateBase monitoring method defined in the regulations of OBD (On-Board Diagnostics) 2 by CARB (California Air Resources Protection Bureau).
Japanese Patent Laid-Open No. 2002-14702 JP 2005-226488 A US Pat. No. 6,531,872 JP 2004-164601 A

  In the conventional abnormality detection method for the timer circuit, as shown in FIG. 12, the predetermined time T, which is the timer value reading interval, is increased by a time (in other words, y is an integer of 1 or more). If this is set to Ty (time corresponding to y count of the timer circuit), the difference between the two timer values read twice after the time Ty (hereinafter, this difference is referred to as detected value x) Then it becomes y.

  However, in actuality, the time when the timer value varies due to the tolerance of the timer circuit (specifically, the tolerance of the operation clock of the timer circuit) varies. Even if there is no variation in the timing at which the microcomputer reads the timer value, the detected value x may not become y. Furthermore, since the timer value is only an integer, the detected value x may deviate from y by more than the tolerance of the timer circuit.

  In the lower part of FIG. 12, n indicates the first read value of the timer value (in other words, the timer value at the start of time measurement of time Ty). The solid line represents the change state of the timer value when the timer circuit tolerance is 0, and the dotted line shows that the change timing of the timer value deviates from the typical timing due to the tolerance of the timer circuit. Represents.

  For example, if the tolerance of the timer circuit is 10%, as shown in FIG. 13, when y = 10, the increment of the timer value in the time corresponding to 10 counts of the timer circuit is 9 to 11. Therefore, the detection value x is also 9 to 11, and the deviation Δ (= | xy−) between the detection value x and y is 1. The deviation amount of 1 is 10% of y (= 10), which is the deviation amount of the tolerance of the timer circuit.

  On the other hand, when the count number y corresponding to the reading interval is a value in which 10% thereof is not an integer, the detected value x deviates from y by more than 10%. That is, the ratio of the deviation amount Δ with respect to y becomes larger than the tolerance of the timer circuit.

  For example, when y = 6, the increment of the timer value in the time of 6 counts of the timer circuit is 5.4 (= 6 × 0.9) if the timer value can be other than an integer. ˜6.6 (= 6 × 1.1), but actually 5 or 6 and the detected value x is also 5 or 6. Therefore, the deviation amount Δ (= | xy−) between the detected values x and y is 1 as in the case of y = 10 as shown in FIG. When y = 6, the ratio of the deviation amount Δ (= 1) to 6 is 16.6%, which is larger than 10% which is the tolerance of the timer circuit.

  In such a conventional abnormality detection method, the normality determination that is the specified range for determining whether or not the timer circuit is normal as the ratio of the deviation amount Δ to the count number y corresponding to the reading interval is small. Since the range can be set narrow, the determination accuracy (abnormality detection accuracy) of whether or not normal is high.

  However, as can be seen from FIG. 13, in order to reduce the ratio of the deviation amount Δ to y, y must be set to a large value. This means that it takes a long time to confirm that the timer circuit is normal. This is because the reading interval of the timer value becomes long.

  For example, if the time of one count of the timer circuit is 1 minute and the tolerance of the timer circuit is 10%, the normal determination range is set to about ± 11% of the count number y corresponding to the reading interval. As can be seen from FIG. 13, y must be set to 10 and it will take at least 10 minutes before the normality of the timer circuit can be confirmed. Even if the normal determination range is expanded to about ± 20% of the count number y corresponding to the reading interval, as can be seen from FIG. 13, y must be set to 6, and the normality of the timer circuit can be confirmed. It will take a minimum of 6 minutes.

  As described above, the conventional abnormality detection method has a problem that it takes a long time to confirm that the timer circuit is normal.

  In particular, in an apparatus in which the control unit is activated by a timer circuit during a period in which the IGSW as the power switch is turned off, such as the electronic control apparatus that performs the above-described evaporation diagnosis processing, the configuration is as follows. There is a request to do. That is, power supply self-holding means is provided so that power supply to the control unit is continued until the control unit itself permits power-off even when the IGSW is turned off, and the control unit is controlled by an abnormal timer circuit. In order to prevent starting at an inappropriate timing, the control unit can detect the abnormality of the timer circuit during the ON period of the IGSW, and confirm that the timer circuit is normal when the IGSW is turned off. If so, the timer circuit is activated and then the power shutdown is permitted. However, if the time required for confirming that the timer circuit is normal becomes long, there is a high possibility that the confirmation cannot be completed during the ON period of the IGSW. Even if is turned off, the normal timer circuit is not activated. This leads to a situation in which processing to be performed when the IGSW is turned off is not performed.

  Further, the above problem is that “when it is determined that the predetermined time T has elapsed since the timer circuit was reset and started, the timer value of the timer circuit is read, and the read timer value (that is, in this case also at the predetermined time T). Similarly, an abnormality detection method such as “determining that the timer circuit is abnormal if the increment of the timer value is not within the specified range” occurs.

  Accordingly, an object of the present invention is to make it possible to confirm in a short time that a timer circuit in an electronic control device is normal.

  According to another aspect of the present invention, the electronic control device includes a control unit that operates when power is supplied when the power switch is turned on, and a timer circuit that operates when power is always supplied regardless of whether the power switch is turned on or off. And a control part measures 1 count time which is the time when the count value (corresponding to the above-mentioned timer value) of the timer circuit changes by one, and determines whether or not the timer circuit is normal based on the measurement result .

  According to such an electronic control device, it can be confirmed in a much shorter time than before that the timer circuit is normal. This is because determination target information (that is, a measured value of one count time) for determining whether or not the timer circuit is normal can be obtained only with approximately one count time of the timer circuit. Whether or not the timer circuit is normal is determined based on whether or not the measured value of one count time is within a specified range. The determination resolution that is the set resolution of the specified range is set to 1 count time of the timer circuit. Therefore, it is possible to reduce the measurement resolution to the one count time, so that the determination accuracy (abnormality detection accuracy) of whether or not the timer circuit is normal can be increased. Furthermore, there is an advantage that it is easy to set a specified range as a judgment value.

Thereon, in the electronic control device according to claim 1, the control unit starts the timer circuit, the time from the start thereof until the count value of the timer circuit detects the first to have changed, one count of the timer circuit It comes to measure as time.

  According to this configuration, the control unit can obtain the determination target information only in one count time after starting the abnormality detection process of the timer circuit, and can confirm that the timer circuit is normal. For this reason, it can be confirmed at the fastest speed that the timer circuit is normal.

On the other hand, in the electronic control device according to the first aspect of the invention , the control unit calculates the time from when the change in the count value of the timer circuit is detected until the next change in the count value is detected. It is measured as 1 count time.

  According to this configuration, since the measurement of one count time is started in a state where the timer circuit is operating reliably, the measurement accuracy of the one count time can be increased. It is possible to improve the determination accuracy (abnormality detection accuracy) of whether or not normal. This is because the response time from when the control unit performs processing for starting the timer circuit to when the timer circuit is actually started is not included in the measured value of one count time.

In the electronic control device according to the second aspect of the invention , the control unit monitors the count value of the timer circuit to detect that the count value has changed. This configuration is advantageous in that it can be reliably detected that the count value of the timer circuit has changed.

Further, the electronic control unit of the Reference Invention 3, the control unit, when it is determined that the measured one count time based timer circuit is not normal, the timer circuit remains actuated, one count time of the current A second count time, which is the time from when the measurement is completed until the count value of the timer circuit next changes, is measured, and whether or not the timer circuit is normal based on the measured second count time. If it is determined that the timer circuit is not normal, the timer circuit is determined to be truly abnormal.

  And according to this structure, the precision which determines with a timer circuit being abnormal can be improved. If the timer circuit is normal, the determination based on the first count time for the first time determines that the timer circuit is normal. Therefore, the effect that the timer circuit is normal can be confirmed in a short time. Still available.

Further, in the electronic control device according to claim 1 , after the timer circuit is activated by the control unit, when the count value of the timer circuit reaches a threshold value set by the control unit, a timer corresponding to the threshold value is set. An output signal indicating that time has elapsed is changed from an inactive level to an active level.

  Then, when starting the timer circuit, the control unit sets the threshold to a value advanced by 1 from the count value at the time of starting the timer circuit. Further, the control unit monitors the output signal of the timer circuit, and measures the time from when the timer circuit is activated until it is detected that the level of the output signal has changed as one count time of the timer circuit. It has become.

  According to this configuration, it can be confirmed that not only the count operation of the timer circuit is normal, but also that the output signal from the timer circuit is normally output.

Hereinafter, an electronic control device according to an embodiment to which the present invention is applied will be described. Note that an electronic control device (hereinafter referred to as an ECU) of the present embodiment controls an engine mounted on a vehicle (automobile). In addition, each embodiment described below is the same in terms of hardware configuration, and therefore the same reference numerals are used for the constituent elements in each embodiment.
[First Embodiment]
First, FIG. 1 is a configuration diagram showing the ECU 1 of the embodiment.

  As shown in FIG. 1, the ECU 1 includes a microcomputer 3 that executes various processes for controlling the engine, and an electric load L such as an injector or a fuel pump that is involved in engine control in accordance with a control signal output from the microcomputer 3. A load driving circuit 4 that drives the microcomputer 3, a timer IC (hereinafter referred to as a soak timer) 5 having a function of automatically starting the microcomputer 3 while measuring the time during which the microcomputer 3 has stopped operating, and the microcomputer 3 A main power supply circuit 7m for outputting a main power supply voltage Vm for operation and a power supply unit 7 having a sub power supply circuit 7s for outputting a sub power supply voltage Vs for operating the soak timer 5 are provided.

  Here, the voltage VB of the plus terminal of the battery 9 of the vehicle (hereinafter referred to as the battery voltage) VB is constantly supplied to the sub power circuit 7 s of the power supply unit 7. Then, the sub power supply circuit 7s always generates and outputs the sub power supply voltage Vs from the battery voltage VB.

  Further, the main power supply circuit 7m of the power supply unit 7 includes a microcomputer IGSW (ignition switch) 11 turned on, a power activation signal Si2 output from the soak timer 5 is at a high level, or a microcomputer. 3 is supplied with a battery voltage VB via a power supply main relay (ML) 13 provided outside the ECU 1 when the power holding signal Sh output from the ECU 3 is at a high level. In the following description, the battery voltage supplied from the positive terminal of the battery 9 via the main relay 13 will be referred to as the battery voltage VP. The main power supply circuit 7m generates and outputs the main power supply voltage Vm from the battery voltage VP supplied via the main relay 13.

  Specifically, first, an IGSW signal Si1 indicating ON / OFF of the IGSW 11 is input to the ECU 1 via the IGSW 11. The IGSW signal Si1 is at a high level when the IGSW 11 is turned on, and is at a low level when the IGSW 11 is turned off.

  The ECU 1 is energized to the coil of the main relay 13 when at least one of the IGSW signal Si1, the power activation signal Si2 from the soak timer 5 and the power holding signal Sh from the microcomputer 3 is at a high level. A main relay drive circuit 15 that short-circuits (turns on) the contacts of the main relay 13 is provided. The main relay drive circuit 15 operates in response to the sub power supply voltage Vs, similarly to the soak timer 5.

  Therefore, when any of the IGSW signal Si1, the power activation signal Si2, and the power holding signal Sh is at a high level, the main relay 13 is turned on, and the battery voltage VP is supplied to the main power supply circuit 7m. The main power supply voltage Vm is output from the circuit 7m to the microcomputer 3. In this example, the battery voltage VP from the main relay 13 is also supplied to the electric load L.

  The power supply unit 7 outputs a reset signal to the microcomputer 3 for a very short time when the main power supply circuit 7m starts to output the main power supply voltage Vm and the main power supply voltage Vm is considered to be stable. It also has. For this reason, when the main power supply circuit 7m starts outputting the main power supply voltage Vm, the microcomputer 3 starts operation (that is, starts) from the initial state.

  On the other hand, the soak timer 5 includes a counter 21 for measuring time, a clock generation circuit 23 that generates a clock of the counter 21 (that is, an operation clock of the soak timer 5), and a count value of the counter 21 (a count of the soak timer 5). The register 25 stores a threshold value to be compared with the timer value of the soak timer 5 or simply the timer value, and the timer value is compared with the threshold value in the register 25. The comparison circuit 27 is provided to change the output level of the power supply activation signal Si2 from low as the inactive level to high as the active level and hold the output state. In the present embodiment, the timer value of the soak timer 5 is typical and is incremented by 1 every minute. That is, the time for one count of the soak timer 5 is one minute.

  Further, the soak timer 5 has the following functions (A) to (D).

  (A) When the “start command” is received from the microcomputer 3 via the communication line 31, the timer value is reset to 0 and the clock generation circuit 23 starts the operation clock output operation from the beginning. That is, the counter 21 and the clock generation circuit 23 are initialized, and the soak timer 5 is activated (reset start).

  For this reason, as shown in FIG. 4, when the “start command” is output from the microcomputer 3 to the soak timer 5 (time t1), a time corresponding to one cycle of the operation clock elapses from that time, When the valid edge (rising edge in the present embodiment) for counting up the counter 21 occurs (time t2), the timer value changes from the initial value 0 to 1. Thereafter, the timer value is incremented by 1 every time a valid edge occurs in the operation clock.

  (B) An arbitrary threshold value is written to the register 25 from the microcomputer 3 via the communication line 31.

  (C) When receiving the “output reset command” from the microcomputer 3 via the communication line 31, the comparison circuit 27 resets the output level of the power supply activation signal Si2 to low.

  (D) The timer value can be read from the microcomputer 3 via the communication line 31.

  Note that the frequency (cycle) of the operation clock generated by the clock generation circuit 23 may be changed by a command from the microcomputer 3. Further, the soak timer 5 may be configured such that the output level of the power supply activation signal Si2 is reset to low by resetting the comparison circuit 27 even when receiving the “activation command” from the microcomputer 3.

  On the other hand, the ECU 1 is provided with a nonvolatile memory (EEPROM in this embodiment) 33 and a buffer circuit 35 that can rewrite data. An IGSW signal Si1 is input to the microcomputer 3 via the buffer circuit 35. Although not shown, the microcomputer 3 includes various signals for detecting the driving state of the vehicle, such as a pulse signal output from a surrounding crank sensor, a signal from a water temperature sensor, and a signal from a vehicle speed sensor. A signal is also input.

  Next, processing executed by the microcomputer 3 will be described.

  First, FIG. 2 is a flowchart showing a process executed when the microcomputer 3 is activated.

  As shown in FIG. 2, when the microcomputer 3 starts operating upon receiving the main power supply voltage Vm from the main power supply circuit 7m, the microcomputer 3 first sets the power holding signal Sh to the main relay drive circuit 15 to high in S110. This is a state in which power is supplied from the main relay 13 to the ECU 1 regardless of whether the IGSW 11 is on or off, and a state in which the main power supply voltage Vm is output from the main power supply circuit 7m (that is, the microcomputer 3 and the main power supply 3). This is to ensure that the ECU 1 is operable. Note that the microcomputer 3 is activated = the ECU 1 is activated, and the battery voltage VP supplied via the main relay 13 is an operating power source for the ECU 1 to operate.

  In step S120, the level of the IGSW signal Si1 input from the buffer circuit 35 is read and the IGSW 11 is turned on in order to determine whether the current activation is caused by the IGSW 11 being turned on or the soak timer 5. It is determined whether or not.

  If it is determined in S120 that the IGSW 11 is turned on, it is determined that the current activation is due to the IGSW 11 being turned on, and the process proceeds to S130.

  In S130, it is determined whether or not the diagnosis of the soak timer 5 is incomplete while the current IGSW 11 is on. The incomplete diagnosis of the soak timer 5 means that the soak timer abnormality detection process described later has not yet been determined to determine whether the soak timer 5 is normal or abnormal.

  If it is determined in S130 that the diagnosis of the soak timer 5 is not completed (that is, the diagnosis is completed), the process proceeds to S150 as it is, but the diagnosis of the soak timer 5 is not completed. When it determines, it progresses to S140, a soak timer abnormality detection process is performed, and it progresses to S150 after that. The contents of the soak timer abnormality detection process will be described in detail later with reference to FIG.

  In S150, it is determined whether or not a condition for incrementing the denominator of the diagnosis frequency for the evaporation purge system is satisfied.

  Here, the diagnosis frequency will be described.

  First, in an automobile electronic control device, there is a RateBase monitoring method as a regulation of OBD2 by CARB. In the RateBase monitoring method, it is necessary to continuously store a diagnosis frequency represented by the following equation.

"Diagnosis frequency = number of diagnoses / operations"
This diagnosis frequency is a frequency at which failure diagnosis is performed, and exists for each of a plurality of diagnosis target items such as an evaporative purge system, a catalytic converter, an oxygen sensor, and the like. The number of operations, which is the denominator of the diagnosis frequency, is data that is incremented when a predetermined operation condition defined by law is satisfied for the diagnosis target item. The number of times of diagnosis, which is a numerator of diagnosis frequency, is data that is incremented when the diagnosis execution condition defined by the automobile manufacturer is satisfied for the diagnosis target item and the determination of normality or abnormality is completed. Furthermore, the CARB regulations require that such diagnostic frequency be greater than or equal to a predetermined value. Further, the denominator and numerator of the diagnosis frequency are stored in the EEPROM 33 and read out to an external diagnosis device connected to the ECU 1 as necessary.

  Against this background, in S150, it is determined whether or not a condition for incrementing the denominator of the diagnosis frequency for the evaporation purge system (for example, a condition that 600 seconds have elapsed after engine start) is satisfied. In the present embodiment, only the diagnosis of the evaporation purge system in which the present invention is used for determining whether or not to perform diagnosis among a plurality of diagnosis target items for which diagnosis frequency must be stored will be described.

  If it is determined in S150 that the condition for incrementing the denominator is satisfied, the process proceeds to S160, where the process of incrementing the denominator of the diagnosis frequency for the evaporation purge system is performed, and then the process proceeds to S170.

  However, the denominator of the diagnosis frequency is not incremented more than once during the ON period of the IGSW 11. The denominator of the diagnosis frequency is data stored in the EEPROM 33 together with the numerator of the diagnosis frequency, the failure diagnosis result, the control learning value, etc., but in S160, the RAM (not shown) in the microcomputer 3 from the EEPROM 33 is used. The denominator read in (1) is incremented on the RAM. Then, the incremented denominator is updated and stored in the EEPROM 33 together with other data by a data saving process performed in S200 described later.

  If it is determined in S150 that the condition for incrementing the denominator is not satisfied, the process proceeds to S170 as it is.

  In S170, as in S120, it is determined whether or not the IGSW 11 is turned on. If the IGSW 11 is still turned on, the process returns to S130. While the IGSW 11 is turned on, the processing of S130 to S170 is repeated every certain time (for example, several tens of milliseconds) sufficiently shorter than one cycle (= 1 minute) of the operation clock of the soak timer 5.

  If it is determined in S170 that the IGSW 11 is turned off, the process proceeds to S180, and it is determined whether or not the soak timer 5 is determined to be normal by the soak timer abnormality detection process in S140 during the current ON period of the IGSW 11.

  If the soak timer 5 is not determined to be normal by the soak timer abnormality detection process (S180: NO), the process proceeds to S200 without performing the process of S190, but the soak timer 5 is determined to be normal by the soak timer abnormality detection process. If (S180: YES), the normal activation process of the soak timer 5 is performed in S190, and then the process proceeds to S200.

  In the normal activation process in S190, a threshold corresponding to a pause time (timer time to be measured) Tw until the ECU 1 and the microcomputer 3 are activated next is set in the register 25 of the soak timer 5, and the soak timer 5 The above-mentioned “start command” is transmitted to and the soak timer 5 is reset and started. Further, a normality determination flag indicating that the soak timer 5 is determined to be normal by the soak timer abnormality detection process during the ON period of the IGSW 11 is turned on (set). The normality determination flag is a flag stored in the backup RAM (the RAM supplied with the sub power supply voltage Vs) or the EEPROM 33, and is turned off (reset) when it is determined NO in S180 and the process proceeds to S200. . In the present embodiment, the pause time Tw is, for example, 5 hours, and in S190, 300 (= 5 × 60 minutes) corresponding to the 5 hours is set as a threshold value in the register 25.

  In S200, the following processing is performed as processing for power off.

  First, data storage for writing the latest value of data to be continuously stored, which is data that must be continuously stored regardless of ON / OFF of the IGSW 11, such as the denominator and numerator of a diagnosis frequency, a failure diagnosis result, and a learning value, to the EEPROM 33 Process. It should be noted that the soak timer 5 diagnosis result (normal or abnormal determination result) by the soak timer abnormality detection process may be stored in the EEPROM 33 by this data storage process, or may be stored in the backup RAM. .

  When the data storage process is completed and all other pause conditions are satisfied, the process of returning the power holding signal Sh to low and the output level of the power activation signal Si2 of the soak timer 5 are reset to low. Processing (specifically, processing for transmitting an “output reset command” to the soak timer 5) is performed.

  Then, since the IGSW signal Si1 is also low at this time, the main relay 13 is turned off, and the power supply from the main power supply circuit 7m to the microcomputer 3 is stopped. For this reason, the microcomputer 3 and the ECU 1 stop operating. When the normal activation process of S190 is performed, when the pause time Tw elapses with the IGSW 11 turned off, the timer value matches the threshold value in the register 25 in the soak timer 5, and the soak timer 5 Since the power activation signal Si2 becomes high, the main relay 13 is turned on and the ECU 1 is activated again. Further, even if the IGSW 11 is turned on before the pause time Tw elapses, the ECU 1 is activated again. On the other hand, when the normal activation process of S190 is not performed, the ECU 1 is activated again only by turning on the IGSW 11.

  Although not shown, the microcomputer 3 performs control processing (engine control) for controlling the engine in parallel with the processing of FIG. 2 (specifically, S130 to S170) when the IGSW 11 is turned on. Process).

  On the other hand, if it is determined in S120 that the IGSW 11 is not turned on, the current activation is caused by the soak timer 5 (that is, activated when the power activation signal Si2 from the soak timer 5 becomes high). The process proceeds to S210.

  In S210, it is determined by referring to the above-described normal determination flag whether or not the soak timer 5 is determined to be normal by the soak timer abnormality detection process in S140 during the ON period of the IGSW 11 immediately before starting this time. That is, if the normal determination flag is on, it is determined that the soak timer 5 has been determined to be normal.

  Then, if it is determined that the soak timer 5 is normal (S210: YES), it is considered that the current activation by the soak timer 5 is an activation at an appropriate timing that the pause time Tw has elapsed after the IGSW 11 is turned off. In the next S220, an evaporation diagnosis process is performed. As described above, the evaporation diagnosis processing includes the system for recovering the evaporation gas from the engine fuel tank, which is closed or pressurized with an actuator, and the pressure fluctuation in the system is detected by the sensor. Then, it is determined whether or not there is a leak in the system.

  When such an evaporation diagnosis process is completed, a process of incrementing the numerator of the diagnosis frequency for the evaporation purge system is performed in the next S230, and then the process proceeds to S240.

  In S230, the molecule read from the EEPROM 33 to the RAM in the microcomputer 3 is incremented on the RAM. The incremented numerator is updated and stored in the EEPROM 33 by the data storage process performed in S200 described above.

  If it is determined in S210 that the soak timer 5 is not determined to be normal by the soak timer abnormality detection process, the current activation is not performed by the normal soak timer 5, and is not activated at an appropriate timing. Therefore, the process directly proceeds to S240 without performing the processes of S220 and S230. This is to prevent the evaporative diagnosis process from being performed at an inappropriate timing and obtaining an erroneous diagnosis result. Note that the determination of S180 is also a process provided for the same purpose.

  In S240, it is determined whether the IGSW 11 is turned on. If the IGSW 11 is not turned on, the process proceeds to S200 described above. Then, the latest value of the data to be continuously saved is written in the EEPROM 33, and then the main relay 13 is turned off, and the microcomputer 3 and the ECU 1 stop operating.

  If it is determined in S240 that the IGSW 11 is turned on, the process proceeds to S250, and an initialization process for restarting the microcomputer 3 is performed in the same manner as when the IGSW 11 is started by turning on the power. Thereafter, the process returns to S130 described above. That is, if the IGSW 11 is turned on during the operation when it is started by the soak timer 5, it is internally initialized and restarted, and the processing after S130 and the engine control processing are performed.

  Next, the soak timer abnormality detection process executed in S140 of FIG. 2 will be described with reference to FIG.

  As shown in FIG. 3, in the soak timer abnormality detection process, first, in S310, it is determined whether or not a diagnosis preparation end flag indicating that the preparation for diagnosis of the soak timer 5 has ended is turned on. The preparation for diagnosis of the soak timer 5 is the processing of S320 and S330 described later. The diagnosis preparation end flag is a flag that is turned off in S340 when the initial value when the microcomputer 3 is activated is off and the processes of S320 and S330 are performed.

  If it is determined in S310 that the diagnosis preparation end flag is not turned on, the process proceeds to S320 and the soak timer 5 is activated. That is, the above-mentioned “start command” is transmitted to the soak timer 5 and the soak timer 5 is reset and started. Next, in S330, a counter (1 count time measurement counter) CT1 for measuring one count time, which is a time during which the timer value of the soak timer 5 changes by 1, is cleared to zero. Then, in the next S340, the diagnosis preparation end flag is turned on, and then the process proceeds to S350.

  If it is determined in S310 that the diagnosis preparation end flag has already been turned on, the process proceeds to S350 without performing the processes in S320 to S340. For this reason, the diagnosis preparation process of S320 and S330 is performed only when the soak timer abnormality detection process is first executed after the IGSW 11 is turned on.

  In S350, the 1-count time measurement counter CT1 is incremented, and in S360, the timer value of the soak timer 5 is monitored. That is, the timer value of the soak timer 5 is read.

  Next, in S370, it is determined whether or not the timer value of the soak timer 3 has changed. Specifically, it is determined whether or not the timer value monitored this time in S360 is inconsistent with the timer value monitored last time in S360.

  If it is determined in S370 that the timer value of the soak timer 3 has changed, the process proceeds to S380. When the soak timer abnormality detection process is executed for the first time, since the previously monitored timer value does not exist, it is always determined as NO (the timer value has not changed) in S370.

  In S380, it is determined whether or not the value of the one count time measurement counter CT1 at that time is within a specified range. The specified range is a range of the value of the 1 count time measurement counter CT1 corresponding to 1 count time considered to be normal, and is a normal determination range for determining whether or not the soak timer 5 is normal. For example, a value obtained by dividing one minute, which is a typical value of one count time, by a count-up cycle of the 1-count time measurement counter CT1 (in this embodiment, the execution cycle of the soak timer abnormality detection process) is used as the center value of the specified range. If the corresponding typical value Ntyp is defined, the specified range is a range from a value smaller than the typical value Ntyp by a predetermined ratio (for example, 20%) to a value larger than the typical value Ntyp by a predetermined ratio (for example, 20%). is there.

  If it is determined in S380 that the value of the 1-count time measurement counter CT1 is within the specified range, the process proceeds to S390, where it is determined that the soak timer 5 is normal, and this is determined as a diagnostic result. Then, the soak timer abnormality detection process is terminated.

  If it is determined in S380 that the value of the one count time measurement counter CT1 is not within the specified range, the process proceeds to S395, where it is determined that the soak timer 5 is abnormal, and this is determined as a diagnostic result. And then the soak timer abnormality detection process is terminated.

  On the other hand, if it is determined in S370 that the timer value of the soak timer 3 has not changed, the process proceeds to S375, and the elapsed time since the start of the soak timer 5 in S320 has reached the timeout time. It is determined whether or not. If the time-out period has not been reached, the soak timer abnormality detection process is terminated as it is.

  The time-out time is a time for detecting that the soak timer 5 is inoperable. In the first embodiment, the time-out time is longer than the normal maximum value of one count time of the soak timer 5, and for example, the soak timer 5 is set to a value shorter than the normal minimum value of the time of 2 counts.

  On the other hand, if it is determined in S375 that the elapsed time from the start of the soak timer 5 has reached the timeout time, the process also proceeds to S395, and it is determined that the soak timer 5 is abnormal. This is stored as a diagnosis result, and then the soak timer abnormality detection process is terminated. In this case, it is considered that the soak timer 5 is not operating.

  In the ECU 1 as described above, when the IGSW 11 is turned on, the main relay 13 is turned on, the battery voltage VP is supplied to the ECU 1, and the main power supply voltage Vm is output from the main power supply circuit 7m. Then, the microcomputer 3 is activated, and the power holding signal Sh to the main relay drive circuit 15 is set high (S110), and the on state of the main relay 13 is ensured.

  In this case, the microcomputer 3 repeats the processes of S130 to S170 in FIG. 2 at regular intervals while the IGSW 11 is turned on. Specifically, the soak timer abnormality detection process of FIG. 3 is repeated at regular intervals until it is determined that the soak timer 5 is normal or abnormal by the process (S130, S140), and the denominator of the diagnosis frequency for the evaporation purge system is determined. It is determined whether or not the condition for incrementing is satisfied at regular time intervals. If the condition is satisfied, processing for incrementing the denominator of the diagnosis frequency for the evaporation purge system is performed (S150, S160).

  Here, in particular, in the soak timer abnormality detection process of FIG. 3, first, as shown at time t1 of FIG. 4, the soak timer 5 is started (S320). Then, as shown at time t1 to time t2 in FIG. 4, the timer value of the soak timer 5 is monitored, and one count time every time the soak timer abnormality detection process is executed until it is detected that the timer value has changed. By incrementing the measurement counter CT1, the time from when the soak timer 5 is started until the timer value first changes is counted as one count time (S350 to S370). Furthermore, as shown at time t2 in FIG. 4, when it is detected that the timer value has changed (S370: YES), the value of the 1-count time measurement counter CT1 at that time (ie, the measured value of 1 count time) Is determined to be within the specified range (S380). If it is within the specified range, it is determined that the soak timer 5 is normal (S380: YES → S390), but if it is not within the specified range, the soak timer 5 is abnormal. Is determined (S380: NO → S395). Also, if the timer value does not change even after the timeout time has elapsed since activation of the soak timer 5, it is determined that the soak timer 5 is abnormal (S370: NO → S375: YES → S395).

  Thereafter, when the IGSW 11 is turned off (S170: NO), the microcomputer 3 confirms whether or not the soak timer 5 is determined to be normal by the soak timer abnormality detection process during the ON period of the current IGSW 11 (S180). Is normal, the normal activation process of the soak timer 5 is performed (S180: YES → S190). That is, a threshold corresponding to the pause time Tw is set in the register 25 of the soak timer 5, and the soak timer 5 is reset and started.

  After that, the microcomputer 3 performs a process of returning the power holding signal Sh to low and resetting the power activation signal Si2 of the soak timer 5 to low as a process of permitting power shutdown to itself (S200). Then, the main relay 13 is turned off, and the power supply from the main power supply circuit 7m to the microcomputer 3 is stopped.

  Thereafter, when the pause time Tw elapses with the IGSW 11 turned off, the power activation signal Si2 from the soak timer 5 goes high and the main relay 13 is turned on. Then, the microcomputer 3 is activated again and sets the power holding signal Sh to high (S110).

  In this case, the microcomputer 3 determines NO in S120 of FIG. 2 and determines YES in S210. After performing the evaporation diagnosis process (S220), the microcomputer 3 increments the numerator of the diagnosis frequency for the evaporation purge system. The process (S230) to perform is performed.

  Thereafter, if the IGSW 11 remains off (S240: NO), the microcomputer 3 returns the power holding signal Sh to low and resets the power activation signal Si2 of the soak timer 5 to low (S200). Then, the main relay 13 is turned off, and the power supply to the microcomputer 3 is stopped.

  If the IGSW 11 is turned on before the pause time Tw elapses, the microcomputer 3 repeats the processes of S130 to S170 in FIG. 2 at regular intervals while the IGSW 11 is turned on as described above. It becomes.

  The above is the operation when the soak timer 5 is normal. If an abnormality occurs in the soak timer 5, the microcomputer 3 determines that the soak timer 5 is abnormal by the soak timer abnormality detection process. In this case, when the IGSW 11 is turned off from on, the microcomputer 3 determines NO in S180 of FIG. 2 and therefore does not perform the normal activation process (S190) of the soak timer 5. This prevents the microcomputer 3 from being activated at an inappropriate timing during the off period of the IGSW 11. For this reason, the process of S210 in FIG. 2 can be omitted.

  In the ECU 1 of the present embodiment as described above, the microcomputer 3 measures one count time of the soak timer 5, and determines whether or not the soak timer 5 is normal based on whether or not the measured one count time is within a specified range. Therefore, it can be confirmed in a much shorter time than before that the soak timer 5 is normal.

  Further, the resolution of the above-mentioned specified range for determining whether or not the soak timer 5 is normal can be reduced to a measurement resolution of the one count time that is shorter than the one count time of the soak timer 5. In addition, it is possible to increase the accuracy of determining whether or not the soak timer 5 is normal. And there also exists an advantage that it is easy to set the prescription | regulation range.

  Further, the microcomputer 3 starts the soak timer 5 in the soak timer abnormality detection process, and measures the time from when the start is detected until the timer value is first changed as one count time of the soak timer 5, It can be confirmed at the fastest speed that the soak timer 5 is normal. This is because it can be confirmed that the soak timer 5 is normal in only one count time after the start of the soak timer abnormality detection process.

  In particular, in the ECU 1 of the present embodiment, the soak timer 5 is diagnosed during the ON period of the IGSW 11, and if the soak timer 5 is not confirmed to be normal when the IGSW 11 is turned off, the soak timer 5 is activated (delayed). In this case, the execution of the evaporation diagnosis process) is stopped.

  For this reason, if the time required for the diagnosis of the soak timer 5 is long, the denominator of the diagnosis frequency for the evaporation purge system is incremented while the IGSW 11 is turned on, but the state that the normality of the soak timer 5 has not been confirmed occurs. If the IGSW 11 is turned off in this state, the denominator of the diagnosis frequency is incremented, but the soak timer 5 is not started, and as a result, the numerator of the diagnosis frequency is not incremented without performing the evaporation diagnosis process. Will occur, leading to the inconvenience that the value of the diagnosis frequency decreases.

  However, according to the soak timer 5 abnormality detection process of the present embodiment, it can be confirmed in a short time that the soak timer 5 is normal. In other words, when the denominator of the diagnosis frequency is incremented, if the soak timer 5 is normal, it is surely confirmed, and the soak timer 5 can be activated to perform the evaporation diagnosis process.

  In the present embodiment, the microcomputer 3 corresponds to a control unit, the soak timer (timer IC) 5 corresponds to a timer circuit, and the IGSW 11 corresponds to a power switch.

  On the other hand, as a first modification, if the diagnosis of the soak timer 5 is not yet completed when the IGSW 11 is turned off, the microcomputer 3 performs the soak timer abnormality detection process at regular intervals until the diagnosis of the soak timer 5 is completed. When it is executed and the diagnosis is completed, the process may proceed to S180 in FIG. Further, as a second modification, the soak timer abnormality detection process may be executed at regular intervals after the IGSW 11 is turned off, and when the diagnosis of the soak timer 5 by the process is completed, the process may proceed to S180 in FIG.

And according to such a 1st or 2nd modification, when the microcomputer 3 starts by turning on IGSW11, the diagnosis of the soak timer 5 can be completed without fail. In addition, according to the soak timer abnormality detection process of the present embodiment, the diagnosis of the soak timer 5 can be completed in a short time. Can be shortened. Therefore, it is advantageous in that battery power consumption can be reduced. Such a modification can be similarly applied to other embodiments described later.
[Second Embodiment]
The ECU 1 of the second embodiment is different from the ECU 1 of the first embodiment in that the microcomputer 3 executes the soak timer abnormality detection process of FIG. 5 instead of the soak timer abnormality detection process of FIG. 3 in S140 of FIG. Is different.

  In the soak timer abnormality detection process of FIG. 5, first, in S410, it is determined whether or not the soak timer 5 has been activated. Specifically, the timer value of the soak timer 5 is monitored (read), and when the timer value is neither 0 nor the maximum value, or even if the timer value is 0, the current IGSW 11 is turned on later. If the soak timer 5 has already been activated in S415, it is determined that the soak timer 5 has been activated.

  If the soak timer 5 has been activated, the process proceeds to S420 as it is. If the soak timer 5 has not been activated, the process proceeds to S415, and the soak timer 5 is activated in the same manner as S320 in FIG. 3, and then proceeds to S420. .

  In S420, the timer value of the soak timer 5 is monitored, and in the subsequent S425, it is determined whether or not the timer value of the soak timer 3 has changed as in S370 of FIG. When the soak timer abnormality detection process is executed for the first time, since the previously monitored timer value does not exist, it is always determined NO (the timer value has not changed) in S425.

  If it is determined that the timer value of the soak timer 3 has not changed, the process proceeds to S427, and the elapsed time from the start of the execution of the soak timer abnormality detection process during the ON time of the IGSW 11 is timed out. It is determined whether or not the time has been reached. If the time-out time has not been reached, the process proceeds to S445 as it is.

  On the other hand, if it is determined in S425 that the timer value of the soak timer 3 has changed, the process proceeds to S430 to determine whether or not the measurement permission flag is turned on. The measurement permission flag is a flag indicating that measurement of one count time of the soak timer 5 is permitted, and the initial value when the microcomputer 3 is activated is off.

  If the measurement permission flag is not turned on (S430: NO), the process proceeds to S435, and after the measurement permission flag is turned on, the process proceeds to S445.

  If the measurement permission flag has already been turned on (S430: YES), the process proceeds to S440, the determination execution permission flag is turned on, and then the process proceeds to S445. The determination execution permission flag is a flag indicating that execution of a determination process (S465 to S475 described later) for determining normality / abnormality based on a measurement value of one count time of the soak timer 5 is permitted. The initial value at start-up of 3 is off.

  In S445, it is determined whether or not the measurement permission flag is turned on. If the measurement permission flag is not turned on, the process proceeds to S450, where the 1-count time measurement counter CT1 is cleared to 0, and then the process proceeds to S460.

  If it is determined in S445 that the measurement permission flag is turned on, the process proceeds to S455 to increment the one-count time measurement counter CT1, and then proceeds to S460.

  In S460, it is determined whether or not the determination execution permission flag is turned on, and if the determination execution permission flag is not turned on, the soak timer abnormality detection processing is terminated as it is, but if the determination execution permission flag is turned on. The process proceeds to S465.

  In S465, the same determination as in S380 in FIG. 3 is performed. That is, it is determined whether or not the value of the 1-count time measurement counter CT1 at that time is within a specified range (normal determination range).

  If it is determined in S465 that the value of the one count time measurement counter CT1 is within the specified range, the process proceeds to S470, where it is determined that the soak timer 5 is normal, and this is determined as a diagnostic result. Then, the soak timer abnormality detection process is terminated.

  If it is determined in S465 that the value of the 1-count time measurement counter CT1 is not within the specified range, the process proceeds to S475, where it is determined that the soak timer 5 is abnormal, and this is the diagnosis result. And then the soak timer abnormality detection process is terminated.

  On the other hand, if it is determined in S427 that the elapsed time has reached the timeout time, the process proceeds to S475, where it is determined that the soak timer 5 is abnormal, and this is stored as a diagnostic result. The soak timer abnormality detection process is terminated. In this case, it is considered that the soak timer 5 is not operating.

  In the second embodiment, only when it is determined twice that the timer value of the soak timer 3 has changed in S425, the determination execution permission flag is turned on in S440, and the determination processing in S465 to S475 is performed accordingly. The timeout time used in the determination of S427 is set to a value that is longer than the normal maximum value of the time corresponding to 2 counts of the soak timer 5, and shorter than the normal minimum value of the time corresponding to 3 counts of the soak timer 5, for example. . However, for example, if it is determined NO in S425 (determined that the timer value of the soak timer 3 has not changed), if the measurement permission flag has already been turned on, the process proceeds to S445 without performing the determination in S427. Specifically, if the determination of S427 is passed once it is determined YES in S425, the timeout time is a value longer than the normal maximum value of at least one count time of the soak timer 5 as in the first embodiment. Can be set to

  In the soak timer abnormality detection process of the second embodiment as described above, when the IGSW 11 is first turned on and the soak timer 5 is not activated (S410: NO), the soak timer 5 is activated (S415). ) If the soak timer 5 has been started from the beginning (S410: YES), the process proceeds without starting the soak timer 5 again. In addition, as the case where the soak timer 5 is started from the beginning, for example, the IGSW 11 is turned off from on, the soak timer 5 is started in S190 of FIG. 2, and then the above-described pause time Tw set in the soak timer 5 is set. In this case, the IGSW 11 is turned on and the microcomputer 3 is activated before the time has elapsed.

  Until the timer value of the soak timer 5 changes, the process is repeated through the route of “S425: NO → S427: NO → S445: NO → S450 → S460: NO”.

  Thereafter, as shown at time t1 in FIG. 6, when the timer value of the soak timer 5 changes first, it is determined YES in S425, the measurement permission flag is turned on (S430: NO → S435), and thereby in S445. The determination is YES, and the increment of the one count time measurement counter CT1 in S455 is started. FIG. 6 illustrates a case where the soak timer 5 has been started from the beginning.

  Then, until the timer value of the soak timer 5 changes to the second time, as shown at time t1 to t2 in FIG. 6, “S425: NO → S427: NO → S445: YES → S455 → S460: NO” The process is repeated along the route. Therefore, every time the soak timer abnormality detection process is executed, the 1 count time measurement counter CT1 is incremented (S455), and the 1 count time of the soak timer 5 is measured by the 1 count time measurement counter CT1.

  Then, as shown at time t2 in FIG. 6, when the timer value of the soak timer 5 changes for the second time, YES is determined in S425, YES is determined in S430, and the determination execution permission flag is turned on ( S440).

  Then, YES is determined in S460 of that time, and the determination processing of S465 to S475 is performed. If the value of the 1 count time measurement counter CT1 is within the specified range, it is normal (S470), and if it is out of the specified range, it is abnormal (S475). ). Even when the timer value does not change even after the timeout time has elapsed since the execution of the soak timer abnormality detection process was first started, it is determined that the abnormality has occurred (S425: NO → S427: YES → S475). ).

  As described above, in the second embodiment, the time from when the change of the timer value of the soak timer 5 is detected until the change of the timer value is detected next is defined as one count time of the soak timer 5. Measurement is performed, and normal / abnormal of the soak timer 5 is determined based on the measured value.

And according to such 2nd Embodiment, since the measurement of 1 count time will be started in the state in which the soak timer 5 is operate | moving reliably, the measurement precision of the 1 count time can be raised, As a result, the accuracy of determining whether or not the soak timer 5 is normal can be improved. This is because the response time from when the microcomputer 3 performs the process for starting the soak timer 5 to when the soak timer 5 is actually started is not included in the measured value of one count time.
[Third Embodiment]
The ECU 1 of the third embodiment is different from the ECU 1 of the first embodiment in that the microcomputer 3 executes the soak timer abnormality detection process of FIG. 7 instead of the soak timer abnormality detection process of FIG. 3 in S140 of FIG. Is different.

  7 is added with S393 and S397 in comparison with the soak timer abnormality detection process of FIG.

  That is, in the soak timer abnormality detection process of FIG. 7, when it is determined NO in S380 (specifically, when the value of the 1-count time measurement counter CT1 is not within the specified range and the soak timer 5 is determined not to be normal), The process proceeds to S393.

  In S393, it is determined whether or not the second determination is NO in S380. If it is determined that the determination is not the second (that is, the first), the process proceeds to S397. After the value of the 1 count time measurement counter CT1 is cleared to 0, the soak timer abnormality detection process is terminated.

  Then, after that, the soak timer abnormality detection process is executed at regular time intervals, and the one-count time measurement counter CT1 is incremented in S350. That is, measurement of one count time is started again. After that, when the timer value of the soak timer 5 changes, YES is determined in S370, and the determination in S380 is performed again.

  In the third embodiment, the timeout time used for the determination in S375 is longer than that in the first embodiment, and the normal maximum of the time corresponding to 2 counts of the soak timer 5 is the same as in the second embodiment. It is set to a value that is longer than the value and shorter than the normal minimum value of the time of 3 counts of the soak timer 5, for example. However, for example, if it is determined NO in S370 (determined that the timer value of the soak timer 3 has not changed), if the process of S397 has already been performed, the process ends without performing the determination of S375. For example, if the determination of S375 is passed once it is determined to be YES in S370, the timeout time does not need to be longer than that of the first embodiment.

  If it is determined in S393 that the second determination is NO in S380, the process proceeds to S395, where it is determined that the soak timer 5 is abnormal, and this is stored as a diagnosis result. Thereafter, the soak timer abnormality detection process is terminated.

  In such a soak timer abnormality detection process of the third embodiment, as shown at time t1 to time t2 in FIG. 8, the soak timer 5 is activated (S320), and the timer value of the soak timer 5 changes first from the activation. This is the same as in the first embodiment in that the time until measurement is measured by the 1-count time measurement counter CT1 (S350 to S370), and whether or not the soak timer 5 is normal is determined based on the measured value (S380). It is.

  In particular, in the soak timer abnormality detection process of the third embodiment, if it is determined that the soak timer 5 is not normal based on the first counted time (S380: NO → S393: NO), the time t2 in FIG. As shown at time t3, with the soak timer 5 operating, the second 1 count time, which is the time from when the measurement of the current 1 count time is completed until the count value of the soak timer 5 changes next, is measured. (S397, S350 to S370). Then, it is determined again whether or not the soak timer 5 is normal based on the measured second count time. If it is determined that the soak timer 5 is not normal, the soak timer 5 is truly abnormal. Determination (abnormality and determination determination) is made (S380: NO → S393: YES → S395).

Therefore, according to such 3rd Embodiment, the precision which determines with the soak timer 5 being abnormal can be improved. Further, if the soak timer 5 is normal, the determination based on the first count time measured for the first time makes a definite determination that the soak timer 5 is normal, so that the soak timer 5 can be confirmed in a short time. The effect is still obtained.
[Fourth Embodiment]
The ECU 1 of the fourth embodiment is obtained by applying the method of the third embodiment to the ECU 1 of the second embodiment. Compared with the ECU 1 of the second embodiment, the microcomputer 3 performs the operation at S140 in FIG. The difference is that the soak timer abnormality detection process of FIG. 9 is executed instead of the soak timer abnormality detection process of FIG.

  9 is added with S473, S480, and S485 compared to the soak timer abnormality detection process of FIG.

  That is, in the soak timer abnormality detection process of FIG. 9, when it is determined NO in S465 (specifically, when the value of the 1 count time measurement counter CT1 is not within the specified range and it is determined that the soak timer 5 is not normal), The process proceeds to S473.

  In S473, it is determined whether or not the second determination is NO in S465. If it is determined that the determination is not the second (that is, the first), the process proceeds to S480 and one count is performed. The value of the time measurement counter CT1 is cleared to 0. Further, in the next S485, the determination execution permission flag is cleared, and then the soak timer abnormality detection process is terminated.

  Then, after that, the soak timer abnormality detection process is executed at regular time intervals, and the one-count time measurement counter CT1 is incremented in S455. That is, measurement of one count time is started again. Thereafter, when the timer value of the soak timer 5 changes, YES is determined in S425, the determination execution permission flag is turned on again in S440, and the determination in S465 is performed again.

  In the fourth embodiment, the time-out period used for the determination in S427 is longer than that in the second embodiment, and is longer than the normal maximum value of the three counts of the soak timer 5, and for example, the soak timer 5 is set to a value shorter than the normal minimum value for the time of 4 counts. However, as described in the second embodiment, once the determination in S425 is YES, if the determination in S427 is passed, the timeout time is at least one count of the soak timer 5 as in the first embodiment. It can be set to a value longer than the normal maximum value of time.

  If it is determined in S473 that the second determination is NO in S465, the process proceeds to S475, where it is determined that the soak timer 5 is abnormal, and this is stored as a diagnosis result. Thereafter, the soak timer abnormality detection process is terminated.

In such a soak timer abnormality detection process of the fourth embodiment, as in the third embodiment, if it is determined that the soak timer 5 is not normal based on the first counted time (S465: NO → S473: NO) The first count time for the second time is measured (S480, S485, S420 to S460), and it is determined again whether or not the soak timer 5 is normal based on the measured second count time (S465). If it is also determined that the soak timer 5 is not normal, it is determined that the soak timer 5 is truly abnormal (S465: NO → S473: YES → S475). Therefore, according to such 4th Embodiment, the same effect as having described about 3rd Embodiment is acquired.
[Fifth Embodiment]
Compared with the ECU 1 of the first embodiment, the ECU 1 of the fifth embodiment is such that the power activation signal Si2 from the soak timer 5 is input to the microcomputer 3 (not shown), and the microcomputer 3 2 in that the soak timer abnormality detection process of FIG. 10 is executed instead of the soak timer abnormality detection process of FIG.

  The soak timer abnormality detection process in FIG. 10 is different from the soak timer abnormality detection process in FIG. Is different.

  That is, in the soak timer abnormality detection process of FIG. 10, when it is determined NO in S310, the process proceeds to S315, and 1 is set as a threshold value in the register 25 of the soak timer 5, and an “output reset command” is transmitted to the soak timer 5. The output level of the power activation signal Si2 is reset to low. Then, the process proceeds to S320, and a process for starting the soak timer 5 is performed. Even if the soak timer 5 receives the “start command” from the microcomputer 3, if the output level of the power supply start signal Si2 is reset, the “output reset command” is not transmitted in S315. May be.

  Further, in the soak timer abnormality detection process of FIG. 10, after incrementing the one count time measurement counter CT1 in S350, the process proceeds to S365, and the power activation signal Si2 from the soak timer 5 is monitored. That is, the voltage level of the power activation signal Si2 is read.

  Then, the process proceeds to S375, and it is determined whether or not the power activation signal Si2 has changed in level (in this embodiment, changed from low to high). Specifically, it is determined whether or not the voltage level monitored this time in S365 is inconsistent with the voltage level monitored last time in S365.

  If it is determined in S375 that the power activation signal Si2 has changed in level, the process proceeds to S380. If it is determined that the level has not changed, the process proceeds to S375. When the soak timer abnormality detection process is executed for the first time, since there is no voltage level monitored last time, it is always determined as NO (the level has not changed) in S375.

  That is, in the soak timer abnormality detection process of the fifth embodiment, as shown at time t1 in FIG. 11, the soak timer 5 is activated in the same manner as in the first embodiment, but at the time of activation, the soak timer 5 is activated. Is set to a value (= 1) advanced by 1 from the timer value (= 0) at the time of activation (S315). Then, the power activation signal Si2 that is an output signal of the soak timer 5 is monitored, and the time from when the soak timer 5 is activated until the power activation signal Si2 is detected to have changed in level is measured as one count time. (S350 to S375). Further, as shown at time t2 in FIG. 11, when the level change of the power supply activation signal Si2 is detected (S375: YES), the value of the 1 count time measurement counter CT1, which is the measured value of 1 count time at that time, is set. Based on this, the normality / abnormality of the soak timer 5 is determined (S380 to S395).

  According to the fifth embodiment as described above, it can be confirmed that not only the count operation of the soak timer 5 is normal but also the power activation signal Si2 is normally output from the soak timer 5. For example, even when the time required for the power activation signal Si2 to change in level becomes longer due to a failure of the comparison circuit 27, it can be determined as abnormal by the determination in S380 (S380: NO → S395), If the power activation signal Si2 does not change in level due to the failure of the comparison circuit 27, it can be determined as abnormal by the determination in S375 (S375: YES → S395).

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to such Embodiment at all, Of course, in the range which does not deviate from the summary of this invention, it can implement in a various aspect. .

  For example, in the second or fourth embodiment, the microcomputer 3 may activate the soak timer 5 by an initialization process performed at the time of activation. By doing so, the time required to complete the diagnosis of the soak timer 5 can be shortened. This is because the time from when the microcomputer 3 is activated to when it is first determined that the timer value of the soak timer 5 has changed in S425 of FIG. 5 or FIG. 9 can be shortened.

  Also, in each of the above embodiments, if it is determined that the soak timer 5 is abnormal by the soak timer abnormality detection process, if the soak timer abnormality detection process is performed again and it is determined that there is an abnormality even in the second execution, it is truly abnormal. You may make it determine with it. And if it does in this way, it can prevent reliably misjudging with abnormality.

  In the first, third, and fifth embodiments (FIGS. 3, 7, and 10), if the diagnosis preparation end flag is turned off before the soak timer abnormality detection process is performed again, the soak timer 5 is started again. can do. In the case of the second and fourth embodiments (FIGS. 5 and 9), the second soak timer abnormality detection process can be performed while the soak timer 5 is operated. You may make it start again.

  On the other hand, the timer circuit may not have a function of starting the control unit while the power switch is off (corresponding to a function of outputting the power supply start signal Si2 in each of the above embodiments).

It is a block diagram showing ECU of embodiment. It is a flowchart showing the process performed when a microcomputer starts. It is a flowchart showing the soak timer abnormality detection process of 1st Embodiment. It is explanatory drawing explaining the effect | action of the soak timer abnormality detection process of 1st Embodiment. It is a flowchart showing the soak timer abnormality detection process of 2nd Embodiment. It is explanatory drawing explaining the effect | action of the soak timer abnormality detection process of 2nd Embodiment. It is a flowchart showing the soak timer abnormality detection process of 3rd Embodiment. It is explanatory drawing explaining the effect | action of the soak timer abnormality detection process of 3rd Embodiment. It is a flowchart showing the soak timer abnormality detection process of 4th Embodiment. It is a flowchart showing the soak timer abnormality detection process of 5th Embodiment. It is explanatory drawing explaining the effect | action of the soak timer abnormality detection process of 5th Embodiment. It is the 1st explanatory view for explaining a problem of conventional technology. It is the 2nd explanatory view for explaining a problem of conventional technology.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Electronic control unit (ECU), 3 ... Microcomputer, 4 ... Load drive circuit, 5 ... Timer IC (soak timer), 7 ... Power supply part, 7m ... Main power supply circuit, 7s ... Sub power supply circuit, 9 ... Battery, 11 ... Ignition switch (IGSW), 13 ... main relay, 15 ... main relay drive circuit, 21 ... counter, 23 ... clock generation circuit, 25 ... register, 27 ... comparison circuit, 31 ... communication line, 33 ... EEPROM, 35 ... buffer circuit

Claims (1)

A control unit that operates when power is supplied by turning on the power switch;
In an electronic control device comprising a timer circuit that is always supplied with power regardless of whether the power switch is on or off,
The control unit activates the timer circuit, and the time from when the timer circuit is activated until it is detected that the count value of the timer circuit is changed for the first time is a time when the count value of the timer circuit changes by one. It is measured as one count time , and based on the measurement result, it is determined whether or not the timer circuit is normal ,
After the timer circuit is activated by the control unit, when the count value of the timer circuit reaches a threshold set by the control unit, an output signal indicating that the timer time corresponding to the threshold has elapsed The inactive level is changed from active level to active level.
In addition, when the timer circuit is started, the control unit sets the threshold value to a value advanced by 1 from the count value at the time of starting the timer circuit. Monitoring the output signal of the circuit and measuring the time from when the timer circuit is activated until the level of the output signal is detected as the one count time;
An electronic control device.

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